Merged in develop

https://github.com/OpenNMS/opennms/pull/5505

@Jeff Gehlbach  sorry I was aware about this. All my work will be targeted Next.

@Antonio Russo how urgent is it to fix this bug? I see you have targeted it for 30.0.0, but we're already in the final sprint for that release. If it can wait for 30.0.1, let's target it to Next instead. Please let me know.

Here is the command execution for opennms:graph-list

admin@opennms()> opennms:graph-list
5 registered Graph Container(s):
Container ID   Label                                    Description                                                                                            Graph Namespaces
application    Application Graph                        Displays all defined applications and their calculated states.                                         [application]
bsm            Business Service Graph                   Displays the hierarchy of the defined Business Services and their computed operational states.         [bsm]
vmware         VMware Topology Provider                 The VMware Topology Provider displays the infrastructure information gathered by the VMware Provi...   [vmware]
nodes          All                                      This Topology Provider displays the topology information discovered by the Enhanced Linkd daemon....   [nodes]
test           GraphML Topology Provider (test-graph)                                                                                                          [acme:markets, acme:regions]

The label for Enhanced Linkd should be: "Enhanced Linkd" and The Graph Namespaces should be a list of:

All,CDP,LLDP,Layer2, Bridge,OSPF,ISIS,Layer3

A check of the provider code is necessary because the LegacyGraphprovider must be enhanced to support layers.

In fact it inherith to use only the DefaultGraphProvider.

It should support multiple graphs